Detergent composition containing a synergistic combination of emc and gelatin as soil suspension agents

ABSTRACT

A BUILT DETERGENT COMPOSITION OF THE NITRILOTRIACETIC ACID TYPE CHARACTERIZED BY IMPROVED SOIL ANTI-REDEPOSITION COMPRISING A SYNTHETIC DETERGENT, A BUILDER OF A POLYPHOSPHATE BUILDER SALT IN COMBINATION WITH SODIUM NITRILOTRIACETATE AND AS A SOIL ANTI-REDEPOSITION AGENT, THE COMBINATION OF CARBOXYMETHYLCELLULOSE AND A GELATIN PROTEIN.

United States Patent Ofice 3,594,324 DETERGENT COMPUSITION CONTAINING A SYNERGISTIC COMBINATION OF EMC AND GELATIN AS SOIL SUSPENSION AGENTS Thomas J. Sayers, Dobbs Ferry, and Edward N. Walsh,

New City, N.Y., assignors to Stauffer Chemical Company, New York, N.Y. No Drawing. Filed May 24, 1968, Ser. No. 731,742 Int. Cl. Clld 3/22, 3/065, 7/46 US. Cl. 252-137 1 Claim ABSTRACT OF THE DISCLOSURE A built detergent composition of the nitrilotriacetic acid type characterized by improved soil anti-redeposition comprising a synthetic detergent, a builder of a polyphosphate builder salt in combination with sodium nitrilotriacetate and as a soil anti-redeposition agent, the combination of carboxymethylcellulose and a gelatin protein.

The present invention relates to detergent compositions containing certain detergent surfactants, certain detergent builders, and certain soil anti-redeposition agent compositions. Particularly, the present invention relates to a built detergent composition containing a detergent compound, a polyphosphate builder salt, sodium nitrilotriacetate, and, a synergistic admixture of carboxy methylcellulose and a gelatin protein, which composition is characterized by improved soil anti-redeposition.

The broad concept of built detergents has been known for some time. This concept envisages the use of additive compounds to improve the effectiveness of detergent compounds. Illustrative of such additive compounds is the synergistic admixture of nitrilotriacetic acid and particularly the sodium salt thereof (hereinafter SNTA) in combination with a condensed polyphosphate, such as sodium tripolyphosphate (hereinafter STP), which is disclosed in US. Pat. 3,356,613 to be very effective in improving the performance of various synthetic detergents. The improved performance generally manifests itself in improving or increasing the soil removal characteristics of the detergent. While built detergents generally show an improvement in soil removal characteristics, they generally lack in another property, e.g., whiteness maintenance or soil redeposition. Whiteness maintenance is generally understood to be the capacity of the detergent composition to suspend the soil in solution once the soil has been removed from the fabric and prevent its redeposition on the washed fabric. If the detergent composition has poor soil suspending properties and the soil is allowed to be redeposited on the washed fabric, the fabric presents a shoddy, grey appearance which is undesirable to the detergent used. Addition of known soil anti-redeposition agents such as carboxymethylcellulose (hereinafter CMC) to built detergents such as the SNTA/STP type provides improvement in preventing soil redeposition but such addition does not completely eliminate soil redeposition.

In accordance with the present invention, a built detergent composition of the SNTA/STP type is provided which is characterized by improved whiteness maintenance comprising:

(a) a detergent substance, preferably of the anionic or nonionic synthetic detergent types or admixtures thereof;

(b) a detergent builder comprising nitrilotriacetic acid and salts thereof in combination with an inorganic, water-soluble, alkaline, condensed polyphosphate builder salt; and

3,594,324 Patented July 20, 1971 (c) a soil anti-redeposition composition comprising an ionic, water-soluble cellulose ether and salts thereof in combination with a gelatin protein such as animal glue or gelatin.

It has been found that the combination of the cellulose ether and the gelatin protein act synergistically in the SNTA/STP built detergent to provide levels of whiteness maintenance which cannot be obtained by the use of either component alone at the same total weight level of addition.

The detergent substances for use in the present invention include anionic synthetic non-soap detergents, nonionic synthetic detergents, ampholytic synthetic detergents and zwitterionic synthetic detergents and mixtures thereof.

These detergent substances are outlined more at length as follows:

(a) Anionic synthetic non-soap detergents can be broadly described as the water soluble salts, particularly the alkali metal salts, of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cg-C13 carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, including those of the types described in United States Letters Patents Nos. 2,220,099 and 2,477,383 (the alkyl radical can be a straight or branched aliphatic chain); sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain from 8 to about 12 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide Where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of a methyl tauride in which the fatty acids, for example, are derived from coconut oil; sodium and potassium salts of SO -sulfonated C1044 a olefins and others known in the art, a number being specifically set forth in United States Letters Patents Nos. 2,486,921, 2,486,922 and 2,396,278;

(b) Nonionic synthetic detergents can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield to a Water soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

As an example, a class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with an hydrophobic base formed by the condensation of propylene oxide with propylene glycol.

The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

1) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols, having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to to moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.

(2) Those nonionic synthetic detergents derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted to the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.

(3) The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene OXide condensate having from 5 to moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(4) Long chain tertiary amine oxides corresponding to the following general formula, R R R NeO, wherein R is an alkyl radical of from about 8 to about 18 carbon atoms, and R and R are each methyl or ethyl radicals. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of amine oxides suitable for use in this invention include dimethyldodecyl amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, dimethylhexadecylamine oxide.

(5) Long chain tertiary phosphine oxides corresponding to the following general formula RR'R"P- 0, wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from 10 to 18 carbon atoms in chain length and R and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of suitable phosphine oxides are:dodecyldimethylphosphine oxide, tetradecyldimethylphosphine oxide, tetradecylmethylethylphosphine oxide, cetyldimethylphosphine oxide, stearyldimethylphosphine oxide, cetylethylpropylphosphine oxide, dodecyldiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipropylphosphine oxide, dodecyldi(hydroxymethyl) phosphine oxide, dodecyldi(Z-hydroxyethyl) phosphine oxide, tetradecyl-methyl-Z-hydroxypropyl phosphine oxide, oleyldimethylphosphine oxide, and 2-hydroxydodecylmethylphosphine oxide.

(c) Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are sodium-3- dodecylaminopropionate and sodium-3-dodecylaminopropane sulfonate.

(d) Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are 3-(N,N-dimethyl-N-hexadecylammonio) propane-l-sulfonate and 3-(N,N-dimethyl-N- hexadecylammonio)2-hydroxy propane-l-sulfonate which are especially preferred for their excellent cool water detergency characteristics.

The anionic, nonionic, ampholytic and Zwitterionic detergent surfactants mentioned above can be used singly or in combination in the practice of the present invention. The above examples are merely specific illustrations of the numerous detergents which can find application within the scope of this invention. Other surfactants within the prescribed classes can also be used.

The foregoing detergent compounds can be made into any of the several commercially desirable composition forms, for example, grannular, flake, liquid and tablet forms.

The detergent builder mixture in the composition of the present invention comprises an inorganic water-soluble, alkaline, condensed polyphosphate builder in combina tion with a water-soluble alkali metal salt of NTA. The inorganic phosphate builders can be any of the salts of acids of phosphorus which possess builder activity. Illustrative are the alkali metal salts of phosphoric acid, e.g., trisodium phosphate, the alkali metal salts of pyrophosphoric acid, e.g., sodium pyrophosphate and the alkali metal salts of polyphosphates such as sodium tripolyphosphates (STP). The above examples of the phosphate builders are given as illustrative and the invention is not intended to be limited thereto nor to alkali metal salts of the specific acids nor specifically to sodium salts, though the sodium and potassium salts are the preferred materials. More preferably, the phosphate builder is sodium tripolyphosphate (STP).

The water soluble alkali metal salts of nitrilotriacetic acid used in the detergent builder have the formula:

CHzCOOH NCH COOH CH COOH wherein a suitable alkali metal cation is substituted for the acidic hydrogens in the above formula. The preferred cation is sodium and the trisodium salt of nitrilotriacetic acid or Na NTA (SNTA) is the preferred compound for use in the detergent builder mixture.

While the builder mixture can contain a variety of components, it is preferred that the builder mixtures contain STP and SNTA in as much as these mixtures exhibit important building properties with a very wide range of active detergent substances and mixtures thereof, and are also compatible with the adjuvants normally used in detergent compositions. The preferred builder mixture of STP and SNTA is preferably constituted so that a molar ratio of STP to SNTA of from about 4:1 to about 1:4 is obtained. Optimum results are obtained within the more preferred molar ratio of STP to SNTA of 3:1 to 1:3. These ratios are calculated on the basis of trisodium nitrilotriacetate and sodium tripolyphosphate.

The solid anti-redeposition agent in the detergent com position of the present invention is an admixture of a gelatin protein and an ionic, water-soluble cellulose ether.

The gelatin protein is the selective hydrolysis product of collagen, the major intercellular protein constituent of the white connective tissue of animal skin and bones. In impure form, the product is animal glue. In highly refined form, the hydrolysis product is pure gelatin.

Glue and gelatin are derived from a number of different animal tissues, bones and hide, as well as from fish. The actual process for the isolation of glues or gelatin can be carried out in an acid or basic medium and the resulting products are known as acid precursor or alkaline precurv sor glues or gelatins. All types of animal-derived glues and gelatins, no matter how processed or what their derivation, can be used in the compositions of the present invention. Preferably, degreased or defoamed animal glues of light color such as chrome glues are utilized.

The ionic, water-soluble cellulose ether is the etherification reaction product of an alkali cellulose with an alkali metal salt of a haloorganic acid. The preferred cellulose ether is carboxymethylcellulose (CMC) and it is prefera'bly used in the form of its sodium salt, though other salts such as the potassium salt can also be used. Other cellulose others can be illustrated by sodium carboxymethyl hydroxyethylcellulose, and the like.

The soil anti-redeposition agent can be composed of mixtures of CMC and animal glues in various weight ratios. A 50%/50% Weight ratio mixture has been found to be effective. Other weight ratio of CMC to animal glue or gelatin within the range of from about 95 to about 95% /5 can also be used. Weight ratios are determined on sodium carboxymethylcellulose and on the weight of the gelatin additive.

The detergent compositions of this invention are preferably compounded so as to provide an aqueous working solution having a pH within the range of from about 7 to about 12, optimum building effects being obtained within this range. In order to establish and maintain a pH in this range in an aqueous washing solution, substantial amounts of alkaline ingredients, such as sodium silicate, can be added to the detergent mixture. This additive is normally added to built detergent systems at low levels of up to 6% as a corrosion inhibitor. Alkalinity control is effected by using about or more, as desired. Preferably, the pH is maintained within the range of from about 9 to about 11.

characteristic of this invention. In the manufacture of liquid detergents water or alcohol vehicles or mixtures of the two, together with solubilizing agents and the like, as known in the art, can be used. These form no limitation on the invention, but are intended to be within the terms of claims calling for compositions consisting essentially of active ingredients and builder mixtures in accordance with the teachings herein.

The detergent compositions of this invention are preferably used to provide a pH in aqueous washing solution within a pH range of from 7 to 12, the optimum building effects being obtained within this range. Washing temperatures usually range from about 80 F. to about 200 F. Fabrics are preferably rinsed and dried after washing.

According to the persent invention these compositions provide excellent cleaning and whiteness maintenance results especially when hard water is used for washing or when high soil levels in the fabrics being washed are encountered, especially inorganic and carbonaceous particulate soils.

The invention will be further illustrated in the examples which follow.

EXAMPLE Detergent compositions, using the components and the amounts set forth in Table I, are prepared by placing weighed amounts of the listed components into /2 gallon jars along with some porcelain balls. Each jar is rolled for 24 hours to insure thorough mixing. Sample D which contains both CMC and animal glue is a detergent mixture prepared in accordance with the present invention. Three different control samples are also prepared, the first having no soil anti-redeposition agent (A), the second containing only CMC (B) and the third containing only animal glue (C). All compositions were tested for soil anti-redeposition action. The results are also reported in Table I.

TABLE I Components and results A B O D I00 100 100 100 20 13g 12g 25 25 5 7 175 Sodium carboxymethylcellulo 5 g 35 Animal glue 2 5 2. 5 1 Sodium metasilicate 25 25 25 25 5 Sodium sulfate (filler). 175 170 170 170 3 34 Washing Solution pH:

Before cleaning 10. 8 10.9 10.85 10.8 1 After cleaning 10. 3 10. 2 10 2 l0. 3 Reflectance before washing 89. 1 89. 0 89. 12 89. 15 Reflectance after washing 32. 31 60. 4 49. 10 72. 8 Reflectance change 56. 81 28. 6 40.02 16. 35 Percent change 63. 7 32. 1 18. 35

zone type.

2 Animal glue- 3 Control 357 The soil anti-redeposition agent is generally utilized in an amount of from about 0.25% to about 3.00%. Preferably, the total amount of soil anti-redeposition agent in the detergent mixture is within the range of about 0.75% to about 1.5%. The remainder of the detergent mixture is preferably composed of from about 5% to about 30% detergent, from about 15% to about builder, from about 3% to about 15% sodium silicate and from about 0% to about 50% of a filler, e.g., sodium sulfate. The amount of detergent and builder used to prepare a detergent composition varies with the ultimate use of the composition and such compositions are easily formulated by one skilled in the art. All percentages herein are by weight unless otherwise specified.

It will be understood by the worker skilled in the art that detergent compositions, including the compositions of this invention, will ordinarily contain various ingredients for special purposes. Thus, they can contain suds builders, suds depressants, anti-corrosion agents, dyes, fiuorescers, perfumes and the like, without interfering with the basic chrome glue, 24 mesh, Bloom value of 60 grams defoamed and of light color.

As can be seen from the data in Table I, the detergent solution having no soil anti-redeposition agent therein (A) showed a very high reduction in the reflectance capabilities of the cloth. This indicates that an excess amount of soil remained on the cloth. The addition of one percent carboxymethylcellulose (B) or 1% animal glue (C) to the detergent compositions partially reduces soil anti-redeposition. However, by the use of /2 percent of CMC and /2 percent animal glue or a total of 1% by weight of the detergent mixture of soil anti-redeposition agent, the reflectance change is markedly reduced indicating substantial soil anti-redeposition action. As can be seen using the same total weight amount of soil antiredeposition agent in the detergent composition, the combination of CMC and animal glue provides a SNTA built detergent with significantly improved properties in the area of soil anti-redeposition.

The evaluation of soil anti-redeposition properties of a detergent mixture was accomplished by: adding a known perature 110 F., agitator 100 rpm; Water 300 p.p.m. 10

hardness, test solution 0.4 gm., laboratory detergent+0.5 gm. Colloidal Graphite per liter of solution.

Five white Indianhead cotton cloths, of selected initial reflectance (as determined on a Hunter Refiectometer, Model D-40) were used for evaluating each detergent formulation.

The invention is defined in the claims which follow.

What is claimed is:

1. A detergent composition consisting essentially of:

(A) 20 percent by weight of an alkali metal linear alkyl benzene sulfonate in which the alkyl group contains from about 9 to about 15 carbon atoms;

(B) 5 percent by weight of sodium tripolyphosphate;

(C) 35 percent by weight of sodium nitrilotriacetate;

(D) 5 percent by weight of sodium metasilicate;

(E) 34 percent by weight of sodium sulfate; and

(F) 1 percent by weight of a synergistic 1:1 soil suspending mixture of sodium carboxymethylcellulose and animal glue.

References Cited UNITED STATES PATENTS 3,356,613 12/1967 Gedge 252137 3,254,028 5/1966 Wixon 2-52137 FOREIGN PATENTS 652,762 11/1962 Canada 252-99 OTHER REFERENCES Prevention of Soil Redeposition in Textile Cleaning Operations by Proteins and Other Polymeric Materials, by W. Fong and H. P. Lundgren, Textile Research Journal, vol. 23, pp. 769-775, November 1953.

LEON D. ROSDOL, Primary Examiner D. L. ALBRECHT, Assistant Examiner U.S. Cl. X.R. 252--89, 132, 138 

